The undefined nuclear region of prokaryotes are also known as
(a) nucleus
(b) nucleolus
(c) nucleic acid
(d) nucleoid
Answer : (d)
In prokaryotic cells, there is no well that defines nucleus or nuclear membrane to bind the nuclear material. Genetic material is Circular DNA in prokaryotes which lies naked in cytoplasm and this region is called as nucleoid.
Therefore, option (d) is correct.